Google has finally started rolling out its latest Android 5.1 Lollipop over-the-air (OTA) update with build LMY47D for the Nexus 7 2012 (3G) model, following its recent factory image roll-out for the 7in tablet.

With the Lollipop update being rolled out in a phased manner, some users may have to wait a bit longer for the OTA notification, depending upon the country or region where they are located.

Such users who missed the OTA notification or cannot access the update via Google's servers for some reason can install the same manually, using the step-by-step guide provided below.

The Android 5.1 OTA update is only for said Nexus devices. Installing the firmware on any incorrect variant could brick the device. Therefore verify the model number of the device before installing OTA update.

This is stock Android 5.1 build LMY47D released by Google, not leaked firmware.

Step 1: Download Android SDK from the Android Development site and follow the instructions on how to install it correctly. For the following process you need the adb and fastboot files which are located in the Paltform-Tools folder

Step 2: Enable developer settings and USB debugging.

Navigate to Settings then About tablet

Tap on build number seven times until a dialogue box appears saying you are now a developer

Return to Settings menu and you should find a new option called Developer options, click on it

Ensure that the Developer options are turned on and the USB debugging is checked

Ensure that Enable OEMunlock is checked, if you are upgrading your Nexus device that has Android Lollipop already installed

Connect your Nexus device to the computer and click OK on the dialogue box that asks you to Allow USB debugging, while connecting to the computer.

Step 3: Place the OTA file in the Platform-Tools directory in order to simplify the process of sending the files to your Nexus phone

Step 4: Ensure that your Nexus tablet is connected to the computer with the device's serial number showing up as a connected device. Then execute the following command: adb devices

Or hold Power and Volume Down buttons together while your Nexus phone is turned off.

Step 6: Now press the Volume Down buttons twice until you have scrolled to Recovery mode. Now press the Power button to select it. This will look like your Nexus device is restarting but an image of an Android with red exclamation mark over it will appear. Now hold the Power button and press the Volume Up button and your device will be in recovery mode.

Step 7: When your Nexus device is in Android system recovery, use the VolumeDown button to highlight apply update from ADB and hit the Power button to select it. Now enter the following command

adb sideload [OTA file].zip

Step 8: The terminal or command prompt will now show a dialogue with the progress of transferring the update to your Nexus phone. Once the update is transferred, you can see the progress bar on the screen

Step 9: Once the update is completed on your Nexus device, it will restart automatically and boot to normal mode